diff options
| -rw-r--r-- | fs/xfs/xfs_log_recover.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index b5eab63eb12..629e88b38bd 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -77,6 +77,11 @@ xlog_buf_bbcount_valid( return bbcount > 0 && bbcount <= log->l_logBBsize; } +/* + * Allocate a buffer to hold log data. The buffer needs to be able + * to map to a range of nbblks basic blocks at any valid (basic + * block) offset within the log. + */ STATIC xfs_buf_t * xlog_get_bp( xlog_t *log, @@ -89,11 +94,26 @@ xlog_get_bp( return NULL; } - if (log->l_sectbb_log) { - if (nbblks > 1) - nbblks += xlog_sectbb(log); - nbblks = round_up(nbblks, xlog_sectbb(log)); - } + /* + * We do log I/O in units of log sectors (a power-of-2 + * multiple of the basic block size), so we round up the + * requested size to acommodate the basic blocks required + * for complete log sectors. + * + * In addition, the buffer may be used for a non-sector- + * aligned block offset, in which case an I/O of the + * requested size could extend beyond the end of the + * buffer. If the requested size is only 1 basic block it + * will never straddle a sector boundary, so this won't be + * an issue. Nor will this be a problem if the log I/O is + * done in basic blocks (sector size 1). But otherwise we + * extend the buffer by one extra log sector to ensure + * there's space to accomodate this possiblility. + */ + if (nbblks > 1 && log->l_sectbb_log) + nbblks += xlog_sectbb(log); + nbblks = round_up(nbblks, xlog_sectbb(log)); + return xfs_buf_get_noaddr(BBTOB(nbblks), log->l_mp->m_logdev_targp); } @@ -142,10 +162,8 @@ xlog_bread_noalign( return EFSCORRUPTED; } - if (log->l_sectbb_log) { - blk_no = round_down(blk_no, xlog_sectbb(log)); - nbblks = round_up(nbblks, xlog_sectbb(log)); - } + blk_no = round_down(blk_no, xlog_sectbb(log)); + nbblks = round_up(nbblks, xlog_sectbb(log)); ASSERT(nbblks > 0); ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); @@ -204,10 +222,8 @@ xlog_bwrite( return EFSCORRUPTED; } - if (log->l_sectbb_log) { - blk_no = round_down(blk_no, xlog_sectbb(log)); - nbblks = round_up(nbblks, xlog_sectbb(log)); - } + blk_no = round_down(blk_no, xlog_sectbb(log)); + nbblks = round_up(nbblks, xlog_sectbb(log)); ASSERT(nbblks > 0); ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); |